Controlling damaging pests on plants grown to provide human food is a constant struggle for growers. Insects can completely destroy a harvest and can cause catastrophic food shortages or financial ruin for the growers. Although many products are effective against insects and mites that damage plants, the products must also be safe enough to be released into the growing environment and safe enough to be applied to parts of the plants that will eventually be consumed.
Organic farming is increasing in popularity. Organic farming restricts the use of compounds that are used for pest control to encourage sustainability and safety. Insecticides can be used in organic farming if they are considered “natural.” Unfortunately, many of the natural insecticides currently available are not potent enough to provide adequate insect control. Further, many of the currently available natural insecticides are not practical to apply or their application is cost prohibitive.
One effective naturally derived insecticide is found in the tissues of many of the plants of the genus Schoenocaulon. The species with the longest history of use, and the most readily available, is the Sabadilla Lily (Schoenocaulon officinale). The plant is indigenous to Central and South America and its seeds have been used for centuries for their insecticidal properties. The seeds contain the alkaloids veratridine and cevadine, both of which are known to be active against arthropods.
Usually the dried seeds are ground to a powder and the powder is applied dry or wetted to the insects. The dust from the seeds, however, can cause eye and nasal irritation. Another disadvantage of using the ground seeds is that the alkaloids break down quickly in the sunlight and do not provide any residual protection.
U.S. Pat. Nos. 2,348,949 and 2,390,911 disclose the use of ground sabadilla seeds with beta-butoxy-beta-prime-thiocyanodiethyl-ether to control house flies. Further, these patents teach heating the seeds and using them as a powder, or mixing them with kerosene to form a sprayable formulation. Neither of these disclosed mixtures of ground sabadilla seeds would be appropriate for organic farming.
Further, insect infestation of human living spaces is a persistent problem. Bed bugs (Cimex lectularius) are known vectors of human disease and are difficult to detect because they are small and often emerge from their hiding spots at night. Currently, there are limited means of capturing and containing bed bugs. Often, an insecticide is the only way to thoroughly treat an environment. Unfortunately, current insecticides are inadequate to provide the mortality rates necessary to completely eliminate an infestation. Another issue that has emerged is that some colonies have developed very high resistance to pyrethroid treatments. The Environmental Protection Agency (“EPA”) has determined that pyrethroid-resistant colonies pose a significant human health risk.
Accordingly, there is a need for new methods of controlling pests on plants and in human living spaces. The methods should be potent, safe to apply, and safe for the environment.